The present invention relates to bottle opening machines for removing crown caps from empty bottles and more particularly to improved bottle opening machines for continuously and automatically removing crown caps from the empty bottles contained in bottle cases which are being conveyed one after another on a conveyance system.
Bottles filled with beer, refreshing drinks, or the like are delivered to consumers, and after consumption of the contents in the bottles, the empty bottles are recovered for bottling beer, refreshing drinks, or the like again. The empty bottles are generally delivered back to a bottling factory in a state wherein they are contained in bottle cases. It is often found that among the recovered empty bottles, some have been manually capped with crown caps, which make it difficult to wash and clean the interior of the respective empty bottles. Thus, there is a necessity for removing such crown caps prior to starting the cleaning operation.
A hitherto known bottle opening machine utilized for the above mentioned purpose is typically so constructed and adapted that cap removing is accomplished by the steps of lowering a pair of pawl means to a position corresponding to the lip portion of the crown cap, causing the pawl means to be actuated until they hold the cap firmly and then forcibly raising up the pawls while the bottle is retained at its shoulder portion so as not to be lifted above the bottle case.
However, it has been pointed out, as drawbacks inherent to this conventional bottle opening machine, that a large power consumption is required for carrying out the intended cap removing operation, that the bottle neck portion is subject to damage during the cap removing operation, and that, because inoperative regions are developed at both the upper and lower dead center points of the raising and lowering movement of the pawl means, continuous and efficient cap removing operation cannot be carried out.
To overcome these problems, we invented an improved bottle opening machine and filed an application (Ser. No. 452,877) for a patent therefor with the U.S. Patent and Trademark Office. The bottle opening machine of the application is provided with a rotary member with a plurality of cap removing sections distributed around the outer periphery thereof, the rotary member being disposed at a position above a roller conveyor on which bottle cases each with a number of empty bottles contained therein are conveyed one after another. In this bottle opening machine, cap removing is carried out continuously by utilizing an increased distance which is developed as the circular movement track of a pawl means in each of the cap removing sections is gradually parted away from the linear movement path of the bottle neck portion of the empty bottles as the bottle cases are conveyed further on the conveyance system.
It should be noted that all of the bottle cases are not always normal and uniform, and sometimes a few bottle cases may have irregularly deformed lateral frames or some foreign material may be on the top or beneath the bottom of the bottles. In the former case, the lateral frame fails to be correctly engaged with synchronizing recesses on the rotary discs or synchronizing discs, resulting in damage of the bottle case or the bottle opening machine itself, while in the latter case, the cap removing sections on the rotary member fail to be correctly engaged onto the bottle necks of the bottles, resulting in damage of the bottle necks or the bottle opening machine itself.
Further, because of the arrangement of the conventional bottle opening machine wherein there is provided a rotary member with the same number of cap removing sections mounted thereon as the number of arrays of bottles contained in the bottle case, it is still necessary that the bottles move through the bottle opening machine even when they are all new bottles which require no cap removing operation. This means that in such as case cap removing is a useless step, and sometimes the existence of the cap removing step inhibits smooth movement of the bottle cases. Another drawback of the conventional bottle opening machine is that some removed crown caps fall incorrectly outside a specific cap receiving basin because the cap removing sections carry them to a predetermined position after their removal from the bottle necks while holding them, and the caps are then discharged therefrom into the receiving basin.
On the other hand, the new bottle opening machine of the aforementioned application is characterized by an arrangement of synchronizing discs or synchronizing guide plates which ensure that the cap removing sections on the rotary discs are correctly engaged with the bottle necks of the bottles contained in the bottle cases which are being conveyed on the conveyance system.
In the bottle opening machine synchronization is achieved in such a manner that the synchronizing recesses on the synchronizing discs or the synchronizing guide plate come into simultaneous engagement with the rear end (rear lateral frame) of the preceding bottle case and the fore end (fore lateral frame) of the following bottle case. However, a problem arises in that, in the case of bottle cases having a considerably low height, the synchronizing discs or the synchronizing plate fail to be engaged with the lateral frames of the bottle case with the result that the cap removing sections are not correctly engaged with the bottle necks of the bottles, whereby the intended cap removing action is not achieved.